Field of the Invention
The present invention relates to a sheet feeding apparatus for feeding a sheet, a sheet conveyance apparatus for conveying a sheet, and an image forming apparatus.
Description of the Related Art
An image forming apparatus such as a printer including a cassette that stores a stack of sheets and can be drawn out from an apparatus body is generally known. This kind of image forming apparatus separates sheets fed from the cassette by a pickup roller from one another with a conveyance roller and a retard roller.
Conventionally, Japanese Unexamined Patent Application Publication No. 2004-299825 has proposed an image forming apparatus including a cassette provided with a guide. The guide is provided downstream of a retard roller in a drawing-out direction and guides a sheet to the retard roller and a conveyance roller. The retard roller wears out from contact with the sheet and the conveyance roller, and thus needs to be replaced after some time. In the case of replacing the retard roller, a user draws out the cassette, cancels the engagement between a claw member and a shaft, and then draws out the retard roller downstream in the drawing-out direction. The claw member is formed on an end portion of the retard roller.
In these years, as a result of miniaturization of image forming apparatuses, retard rollers have been miniaturized, and the space around a retard roller has also become smaller. In the image forming apparatus described in Japanese Unexamined Patent Application Publication No. 2004-299825, it has been difficult to replace the retard roller in the case where, for example, the space for holding an engagement claw is narrow.